在已生成结果后重新排序sql

Is there a way to resort a mySQL sql after the results are already generated.

I have a sql that gets the results I want to display basically but the way I want to sort them depends on the result themselves. Have provided some pseudo code for clarity.

$sql = "SELECT * FROM post_info WHERE poster = 'login_user' OR replier = 'login_user'";

if ('login_user' == $row['poster']) { //sort by one column } 
else { //sort by a different column }

You can sort conditionally from within the query with a CASE statement.

ORDER BY (CASE
  WHEN poster = 'login_user' THEN col1
  ELSE col2
END)

$sql = "SELECT *, if(poster='login_user', 1, 0) as idx FROM post_info WHERE poster = 'login_user' OR replier = 'login_user' order by idx desc";

or

$sql = "SELECT * FROM post_info WHERE poster = 'login_user' UNION SELECT * FROM post_info WHERE replier = 'login_user'";